Wyniki wyszukiwania - Biblioteka Nauki

1

Reakcje fizjologiczne w warunkach pogorszonej jakości powietrza

100%

Szulc D. , Wargocki P. , Fang L. , Zhang X. J.

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tom nr 10

26--32

PL

Subiektywny eksperyment, składający się z dwóch części, został przeprowadzony w celu zbadania efektów działania urządzeń przeznaczonych do oczyszczania powietrza na warunki zdrowotne, komfort i wydajność pracy. Dwa typy urządzeń, wolnostojący plazmowy oczyszczacz powietrza oraz jednostka kasetonowa z nawiewem obwodowym z funkcją oczyszczania powietrza, zostały wykorzystane w niezależnych częściach eksperymentu. W przeciągu około pięciu godzin ekspozycji trzydziestu dwóch uczestników wykonało różne zadania, składające się z dodawania, mnożenia i przepisywania tekstów. Pomiary obiektywne zostały przeprowadzone głównie w celu zbadania górnych dróg oddechowych i parametrów powietrza wydychanego (pomiary funkcji życiowych, dróg oddechowych, pomiary z wykorzystaniem pasków Suunto memory belts). Ponadto uczestnicy ocenili odczuwalną jakość powietrza wewnętrznego, komfort termiczny oraz wypełnili kwestionariusze dotyczące Syndromu Chorego Budynku (SBS). Wyniki badań pokazują, iż użycie oczyszczaczy powietrza miało pozytywny wpływ na odczuwalną jakość powietrza wewnętrznego i zredukowało odsetek osób niezadowolonych z jakości powietrza wewnętrznego. Zaobserwowano różnice w pomiarach fizjologicznych przeprowadzonych na uczestnikach pomiędzy ekspozycjami z aktywną i bierną pracą oczyszczacza powietrza (podzespół oczyszczający został zdemontowany). Obserwacje sugerują, iż w pogorszonej jakości powietrza wewnętrznego uczestnicy prawdopodobnie wkładali więcej wysiłku, w celu wykonania testów dotyczących wydajności pracy. Wśród uczestników wrażliwych na jakość powietrza wewnętrznego (w tym astmatyków i alergików) zauważono większy wpływ ekspozycji na pracę układu oddechowego (zmniejszone wartości częstotliwości oddychania oraz maksymalnego strumienia powietrza usuwanego z dróg oddechowych w odniesieniu do osób niewrażliwych). Wyniki sugerują, iż osoby wrażliwe na jakość powietrza mogą mieć większe skłonności do zmian w drogach oddechowych w tym zapalenia w warunkach pogorszonej jakości powietrza. W oparciu o wyniki badań można wywnioskować, że wykorzystane pomiary fizjologiczne, przeprowadzone na uczestnikach eksperymentu, mogą pomóc wyjaśnić otrzymane pomiary laboratoryjne, w których testowano wpływ jakości powietrza wewnętrzneo na wydajność pracy.

EN

A subjective experiment consisting of two phases has been conducted to evaluate the effect of air purification devices on human health, comfort and performance. Two types of devices, a portable plasma streamer and round flow cassette ceiling mounted air purifiers were used in a two phase experiment. During ca. five hours of exposure thirty two participants performed different tasks comprising addition, multiplication and text typing. Objective measurements were carried out to examine the upper respiratory tract and the parameters of exhaled air (measurements of vital signs changes, lung functions and measurements with Suunto memory belts). Moreover the subjects evaluated perceived air quality, thermal comfort and reported the intensity of their SBS symptoms in questionnaires. The results show that the operation of the air purifiers improved perceived air quality and reduced the percentage of the dissatisfied with air quality. The differences in physiological measurements carried out on subjects were observed between the condition when the air purifier was on and off (the purification part of the device was removed). Observation suggest that in poor indoor air quality condition subjects probably exerted more effort in order to perform performance tasks. Subjects sensitive to air quality, including those with allergies and asthma, were found to have their measured parameters of peak expiratory flow (PEF) and respiration rate (RR) at a lower level compared to those of non-sensitive subjects. The results suggest that subjects sensitive to air quality may have an increased tendency to changes in respiratory tract (e.g. irritation or inflammation) when they are exposed to polluted air. Based on the results of the experiment it is possible to conclude that physiological measurements carried out on subjects might help to explain the obtained laboratory results in which the impact of indoor air quality was tested on human performance at work.

2

Laser aerosol time-of-flight mass spectrometry analysis of individual aerosol particles from photooxidation of toluene

88%

Hao L. Q. , Zhou L. Z. , Gu X. J. , Fang L. , Zhang W. J.

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2006

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tom Vol. 36, nr 1

5-13

EN

A laser aerosol time-of-flight mass spectrometry (ATOFMS) that can be used for real-time measurement of the size and composition of individual aerosol particles has been designed and manufactured in our laboratory. Particles are introduced into the instrument through a particle beam interface, sized by measuring the delay time between two scattering lasers, and compositionally analyzed using a laser desorption/ionization linear-time-of-flight mass spectrometry. Secondary organic aerosol particles from the photooxidation of toluene in the CH3ONO/NO/air mixture were generated in a home-made smog chamber and measured using it. Experimental results showed that the individual aerosol particles from photooxidation of toluene can be measured in real-time by this instrument. This unique capability is impossible in off-line methods such as chromatography and chemical method.

3

Isolation and characterization of phosphate-solubilizing bacteria from mushroom residues and their effect on tomato plant growth promotion

75%

Zhang I. , Wang P. , Fang L. , Zhang Q.-A. , Yan C. , Chen J.

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tom 66

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nr 1

EN

Phosphorus is a major essential macronutrient for plant growth, and most of the phosphorus in soil remains in insoluble form. Highly efficient phosphate-solubilizing bacteria can be used to increase phosphorus in the plant rhizosphere. In this study, 13 isolates were obtained from waste mushroom residues, which were composed of cotton seed hulls, corn cob, biogas residues, and wood flour. NBRIP solid medium was used for isolation according to the dissolved phosphorus halo. Eight isolates produced indole acetic acid (61.5%), and six isolates produced siderophores (46.2%). Three highest phosphate-dissolving bacterial isolates, namely, M01, M04, and M11, were evaluated for their beneficial effects on the early growth of tomato plants (Solanum lycopersicum L. Wanza 15). Strains M01, M04, and M11 significantly increased the shoot dry weight by 30.5%, 32.6%, and 26.2%, and root dry weight by 27.1%, 33.1%, and 25.6%, respectively. Based on 16S rRNA gene sequence comparisons and phylogenetic positions, strains M01 and M04 belonged to the genus Acinetobacter, and strain M11 belonged to the genus Ochrobactrum. The findings suggest that waste mushroom residues are a potential resource of plant growth-promoting bacteria exhibiting satisfactory phosphate-solubilizing for sustainable agriculture.

4

Rapid detection of trace chloroethylenes sing laser mass spectrometry

75%

Ma J. , Ding L. , Fang L. , Zheng H. , Gu X. , Zhang W.

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2005

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tom Vol. 35, nr 2

395-402

EN

Laser mass spectrometry is a new chemical trace analysis method with high selectivity, sensitivity and speed. The mass-resolved resonance-enhanced multiphoton ionization (REMPI) spectra of chloroethylenes-trichloroethylene and tetrachloroethylene are firstly reported in the range 305.0-325.0 nm. The mass-resolved excited spectra and laser power index of fragment ions CCl+ are presented. The experimental results indicate that 310.8 nm is the suitable ionization wavelength for detection of trichloroethylene and 322.5 nm for the detection of tetrachloroethylene in this wavelength range. The detection limits of these two chloroethylenes of concentration range expressed in ug/L are presented.

5

Mass spectral analysis of the aged 1,3,5-trimethylbenzene secondary organic aerosol in the presence of ammonium sulfate seeds

63%

Huang M. , Xu J. , Cai S. , Liu X. , Hu C. , Gu X. , Fang L. , Zhang W.

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nr 4

EN

The ammonium sulfate ((NH₄)₂SO₄) seed aerosols commonly found in the Chinese urban atmosphere could affect the formation and aging of secondary organic aerosols (SOA). Aging of aromatic SOA is performed using UV-irradiation of 1,3,5-trimethylbenzene (135-TMB)/CH₃ONO/NO/air mixtures with high concentrations (~100 μg/m³) of (NH₄)₂SO₄ seeds in the laboratory chamber in this study. The particulate products of SOA were measured using an aerosol laser time-of-flight mass spectrometer (ALTOFMS) in real-time, and fuzzy c-means (FCM) was applied to the mass spectra organic species for clusters. Experimental results indicated that methylglyxoal, 2-methyl-4-oxo-2-pentenal, 4-methyl-1H-imidazole, 4-methyl-imidazole-2-acetaldehyde, and other imidazole derivative compounds are the principal products in the aged particles. Imidazole compounds that can absorb solar radiation effectively were newly detected in the aged 135-TMB SOA with high concentrations of (NH₄)₂SO₄ seed aerosols. These would provide new information for discussing the 135-TMB SOA aging mechanism.